Gear grinder



Jan. 1o, 192s. 1,655,921

H. G. SHAFER f GEAR GRINDER Filed April 25, A1924 3 Sheets-Sheet l 4 Han/gy G. Shafer,

Jan. 10, 1928. 1,655,921

H. G. sHAFER GEAR GRINDER Filed A 'l 25. 1924 3 Sheets-Sheet 2 j zo 16 J3.- l lj 1* 12 2F11 la 3 6 K nff 56A' 36? Ik zo 57j", il 6J H 35 `l 7 l J7 T T; 44 55 -1 45 j 54 25 4 a e5 N A s...

' INVENTOR. '"7 Harvey G. J/fer,

J 6 BY ATTORNEYS H. G. SHAFER GEAR GRINDER Jan. 10, 1928.

Filed April 25, 1924 5 Sheets-Sheet 5 7 ab? f4 i 46' 1m mme.

Harn/g 5ba/Eer,

Fatented dan. l0, 1928.

uurr En STATE 11;.;

mmm-mu- I-IRVEY G. SHAFJEFI, F FNDFNAFLJES, INDIiNllr.

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Application :tiled April 25,

llfy invention relates to improvements in gear grinding or cutting machines and has for one of its objects that of providing an improved means for automatically feeding t the work to the cutter for the cutting or grinding of gear teeth. Another object of my invention is to provide means for automatically indexing the gear to present a new tooth to be cut after the cutting operation litt has been completed on the preceding tooth.

@ther objects and advantages of my invention will appear more fully hereinafter.

For the purpose of describing my invention ll have illustrated one embodiment thereof in the accompanying drawings in which Fig. 1 is a side elevation of a gear grinding machine embodying my invention.

Figo 2 is a plan view thereof;

Fig. 3 is a sectional view taken on the line 3 3 of Fig. 2;

Fig. d is a sectional view taken on the line 4 4 of Fig. 2;

Fig. 5 is an enlarged detail plan partly in section of the werft-supporting and indexing mechanism;

Fig. 6 is a sectional view taken on the line om@ of Fig. 5;

Fig. l

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l' is a sectional view taken on the line IT-7 of Fig. 5;

Fig. 8 is a detail perspective of the guiding and indexing raclr.

lin the embodiment of the invention illustrated, lf provide a suitable base or table 1a, which carries a supporting arm 2 having mounted thereon the usual grinding wheel shaft 3 supporting .and driving the grinding wheel t. 'llhe shaft 3 is preferably mounted in a head of the usual construction which permits various angular adjustments of the grinding wheel. So much of the structure comprises the usual bed and grinding wheel of the commercial type of universal grinder now in use for various purposes.

Mounted on the table 1EL is a supplemental base 1 secured to the table 1a by bolts or keys 1b and provided with sliding bed 5 which is adapted to reciprocate substantially longitudinally of the axis of the grinding wheel. This bed 5 is provided with the usual undercut beveled guideways 6 engaging corresponding guideways 7 on the base 1 to insure accurate movement of the table and prevent the same from 'vertical displacement. This bed 5 is elevated above the base 1 to provide a clearance between the underside of the top fio tid

19g-t. Serial No. lh

and the bed and the top of the hase 1 to accommodate the spacing and indexing mechanism for the gear.

rlhe gear to be ground is rotatably mounted on a supporting and clamping bench which comprises a hub support 8 having a base 9 resting on the top of the table 5 overan opening 10 in said table and provided with an annular Harige 11 fitting within said opening to properly position the base and the hub. A spindle 12 extends through the hub, being rotatably mounted therein in suitable bushings 13 and the upper end of this spindle is provided with an integral collar lll adapted to rest upon the top of the hub 8, a washer being interposed between the collar and the top of the hub. rlhe spindle 12 is extended beyond this collar and is adapted to support the blanlr 16 to be cut or ground. 'Fhis blank fits on a bushing 17 surrounding the top end of the spindle, which bushing at its lower end rests on the collar 14, a washer 18 being interposed between the bottom of the blank and an annular Flange 19 on the bushing. ilfhe gear blank is clamped in position on the upper end of the spindle between the collar 1t and a clamping member 2() which is held clamped down on the top of the hub of the blank by means of a screw nut 21 threaded on the top of a screw 22 which in turn is threaded into the end of the spindle.

rFhe master gear 2t is supported on the lower end of the spindle 12, being adapted to be clamped between a nut 25 threaded on the lower end of the spindle and a shoulder on the spindle 12, a washer 26 interposed between the gear and the bottom end of the hub support.

By the above construction, it will be noted that the master gear and blank form a unitary structure in which the master gear and blank may be clamped together, and this unitary structure may be mounted on the sliding bed 5 by means of suitable bolts 2'?.

The master gear is adapted to have rolling engagement with a guiding and indexing rack 28 composed of two sections 28a and 28h, one of which, the section 28 is movable relatively to the other and with the sliding bed 5, while the other is relatively stationary with respect to the bed. This rack is mounted on a sliding raclr table 29 supported on the base 1, being adapted to tit in a beveled slot in said base and movable at dll tid

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.lllti right angles to the line of movement of the bed 5 in order to adjust the rack to gears of different sizes. To this end, in a bracket 30, offset from the base 1, I provide a stop screw 31 which is screw-threaded in the bracket and provides at its inner end, a stop for limiting the outer movement of the table 29 so that, by rotating the stop screw 31, the position of the table 29, and with it the rack 28. may be nicely adjusted. After the stop screw has been adjusted, it may be held inits adjusted position by a set screw 32. In order that the table 29 may be moved to disengage the rack 28 from the master gear to permit a free rotation of the gear blank for the purpose of inspection, etc., during the grinding operation` I provide a sliding bolt 33 likewise mounted in the bracket 30. The top of this bolt is provided with a socket 34 adapted to receive an eccentric pin 35 on a vertically extending spindle 36 mounted in a journal 37 above the bolt. A handle 38 is provided for rotating the spindle and it will be noted that one side of the journal is extended to formy a stop 39 to be engaged by the handle and for preventing the rotation of the spindle beyond a predetermined point. This sliding bolt is connected by a stem'40 which, at its inner end is threaded into a screw threaded socketin the end of the table 29 so that the length of the connection between the bolt and the table maybe adjusted to correspond to the adjustment of the stop screw 31. The stem is provided, on one side, with a stationary collar 42 which abuts against the bolt 33 whereby, as the bolt is moved inward, the stem and with it the sliding table will recelve a corresponding movement. A coil spring 43 is interposed between the opposite end of the collar and the knurled end 44 of the stem 40, which' springresiliently holds the table against the stop screw 31 when the spindle is rotated to move the table outj wardly. By this resilient holding means, in v.event of foreign particles becoming interposed between the teeth of the gear and tooth of the rack, the rack may move -relatively to the gear without destroying the holding parts of the table.

The movable section 28b of the rack 28 overlaps the stationary section on the line 45 for a distance of two teeth and this movable section is provided with a lip 46 seating into a socket 47 on a slide bar 48 provided at its outer end with an extension stem 49 having an adjustablel stop nut 50. This nut is adapted to be engaged by a downwardly extending iiange 51, on the end of the bed 5 after the bed has been moved a redetermined distance. Carried by the be is a cam 52 adapted to engage a pin 53 on a spring pressed latch linger 54. This fin er, when the bed is retracted to the rig t, looking at Fig. 5, is released by the cam 52 and allowed to project into a socket 55 on the slide bar 48 to hold the slide bar in its retracted position and as the end of the finger 54 is slightly tapered to tit the correspondingly tapered socket 55 the slide .bar is properly spaced. thereby properly spacin the section 28b of the rack.` As the bed 5 is retracted to the left, looking at Fig. 5, the cam 52 will engage the pin 53-re tracting the linger 54 to permit the slide bar to be moved' forward when the flange 51 of the bed engages the coil spring 56 surrounding the stem 49.

The bed 5 is reciprocated by means of a. cam wheel 57 having a cam slot 58. This cam slot is engaged by a roller supported upon a pin 59 mounted in a slide bar 6() which slide bar is in turn provided with a clamp 61 arranged to clamp on a link arm 62 secured to the bed 5. This cam wheel is mounted on a shaft supported in suitable bearings 62 carried by a base 63 which like the base l is clamped on the table l"L by screws or keys 64. By thus mounting the gear carrying and indexing mechanism on the supplemental bases I provide a self-contained Vunitary structure which may be used with the present type of commercial grinding machine without modiiication of the machine.

In operation, the master gear and the blank to be ground are clamped in position on the clamping bench, the nuts 21 and 25 at the opposite ends of the spindle 12 serving to clamp the master gear and blank on the spindle while permitting the spindle to rotate in the hub support 8. Care is exercised in clamping the two gears on the spindle to insure the teeth of the blank being in perfect alignment with the teeth of the master gear. The unit thus formed is then bolted to the sliding bed 5 by means of the bolts 27 which extend through the base of the hub support 8 and into the top ot the sliding bed. After the blank and master gear are 'mounted on the sliding bed 5 the rack 28 is adjusted into engagement with the master gear. The rotation of the cam wheel 57 reciprocates the bed 5 projecting the same to the right, looking at Fig. 1, during which sliding movement the master gear makes rolling engagement with the rack 28. This rolling engagement of the master gear with the rack rotates the spindle and imparts a` corresponding rotation to the blank so thatI the blank moves into engagement with the grinding wheel with a rolling movement. One face of one tooth, or if desired, opposite faces of two teeth, are then ground by the wheel and as the sliding table continues in its movement to the right the master gear makes engagement with the movable section 28b of the rack and passes ed of the relatively stationary section. At this time the nut 50 is engaged by the flange 51 of the lll) lllll lill lill

nersaeal moving table and the section 28b ot the rack moves vvith the sliding bed 5 so that, during the rest ot the movement ot the bed 5, the master gear will not be rotated. During this torvvard movement ot the pin 53 on the latch tinger 54 rides ott the cam member 52 and is projected into the socket in the bar 48, thus holding the movable section 28 of the raclr stationary during a portion ot the return movement et the bed 5. 'lhe effect ot this is the equivalent ot advancing the movable section 28 ot the rack one tooth so that., during the return reciprocating movement ot the bed, the master gear vvill have been advanced one tooth relatively to the rack section 28a and a. new tooth, upon the turther reciprocation of the bed will be presented to the grinding Wheel. By the time the ldange 51 has moved to compress the spring 56 and the cam 52 moved to disengage the latch tinger 5l, the master gear vvill have heen rotated into engagement with the. stationary section 28 ot the rack and the movable section 281 will then move to its initial position Without atitecting the master gear.

llllhile l have shown and described my invention as being used for grinding blanks which have already been cut, it is obvious that the same may be used 'for initially cutting blanhs. ln this event, a rotary cutter vvilll be substituted :tor the grinding vvheel.

ln order to maintain the movable section 2d in pertect alignment with the stationary section 28a et' the rack 28, the movable section 28h is provided vvith a tongue 63 sliding in a groove 6d in the table 29. This construction prevents any tendency on the part ot the raclr section 28b trom moving' transversely to the section 28a.

l claim as my invention:

l. ln a gear grinding machine the combination vvith a grinding Wheel, ot a sliding bed, means 'tor reciprocating said bed relatively to said vvheel, a master gear rotatably mounted on said bed, means tor supporting a blanlr to rotate with said master gear, a raclr vvith which said master gear has rolling engagement during the reciprocation ot said bed and a second rack movable relatively to said lirst rack and arranged to be moved to rotate said gear independently ot the'nrst raclr alter the blank has moved out oit engagement vvith the grinding Wheel.

2. ln a gear grinding machine the combination with a grinding Wheel, ot a sliding bed., means tor reci rocating said bed relatively to said grinding Wheel, a master gear rotatably mounted on said bed, means tor mounting a blanlr to rotate with said master gear, a raclr relatively stationary with respect to said bed and With which the master gear makes rolling engagement during its reciprocation and means operated by the movement 'ot said bed for rotating `said master gear independently of said rack after the blank has moved out of engagement `with the grinding Wheel.

3. In a gear grinding machine the combination with a grinding Wheel, ot a sliding bed. means tor reciprocating said bed relatively to said grinding wheel, a master gear rotatably mounted on said bed, means :tor securing a blank to rotate with said gear, a two section rack with which said master gear is arranged to make rolling engagement during the reciprocation ot said bed, one ot said sections being relatively stationary to the bed and the other section being arranged to be moved with the bed during a predetermined portion ot its movementto rotate the master gear independently ot said first rack section.

d. ln a gear grinding machine, the combination with a. grinding vvheel, ot a sliding bed, means tor reciprocating said bed relatively to said grinding Wheel, a master gear rotatably mounted on said bed, means :tor securing a blanlr to rotate vvith said master gear, a raclr relatively stationary with respect to said bed and With which the master gear makes rolling, enga ement during the reciprocation ot said be means operated by the reciprocation ot said bed tor rotating said master gear independently ot said raclr and means tor adjusting said raclr to accommodate gears ot diderent sizes.

5. ln a gear grinding machine the combination vvith a grinding Wheel, ot a sliding bed, means tor reciprocating said bed relatively to said grinding vvheel, a master gear rotatably mounted on said sliding bed, means tor securing a gear blanlr to rotate with said master gear, a raelr having a part .relatively stationary with respect to said sliding bed and a part movable With said sliding bed to rotate said gear independently ot said stationary part and means for adjusting said raclr to accommodate gears ot diderent sizes.

t5. ln a gear grinding attachment tor grindin machines, the combination vvith a base, o a raclr transversely adjustable on said base, a bed longitudinally reciprocable on said base, and a blanlr and master gear carrier bodily removably mounted on said sliding bed arid adapted to support said master gear in engagement vvith said raclr to cause the same to be rotated when the sliding table is reciprocated and means on said base tor rotating said master gear independently oit the raclr.

7. lin a gear grinder the combination `with a grinding Wheel, ot a. base, a sliding-bed reciprocally associated vvith said grinding Wheel, a rack stationarily mounted with respect tosaid sliding bed, a master Gear and blank support tor supporting said master till ttl

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gear in engagement With said raclr and the i lank in a position to'be engaged by said grinding wheel comprising a hub removably mounted on said sliding table, a shaft mounted in said hub, means for removably securing a master gear at one end of said shaft in a position to engage said rack and means for securing a blank at the other end of said shaft in a position to be enga ed by said grinding wheel, said hub shat and` master ear in a position to be engaged by said rac and the lank in position to be engaged by said grinding wheel, means for positioning said rack carryin table with the 20 rack in definite relation to tie master gear, means for manipulating said rack carrying table to disengage the same from said master gear without affecting said positioning means, and means for rotating said master gear independently of said rack.

In Witness whereof I. HARVEY G. Sir/wml,

have hereunto set my hand :1t Indianapolis,

Indiana, this 21st day of April, A. D. one thousand nine hundred and twenty four.

HARVEY G. SHAFER. 

